Re: [PATCH v2 2/3] spi: axi-spi-engine: use __counted_by() attribute

[Gustavo A. R. Silva]

On 04/03/24 10:04, David Lechner wrote:
> This adds the __counted_by() attribute to the flex array at the end of
> struct spi_engine_program in the AXI SPI Engine controller driver.
>
> The assignment of the length field has to be reordered to be before
> the access to the flex array in order to avoid potential compiler
> warnings/errors due to adding the __counted_by() attribute.
>
> Suggested-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo

> ---
> v2 changes:
> * Reordered assignment of length field.
> ---
>   drivers/spi/spi-axi-spi-engine.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
> index d89f75170c9e..a8f626165f44 100644
> --- a/drivers/spi/spi-axi-spi-engine.c
> +++ b/drivers/spi/spi-axi-spi-engine.c
> @@ -75,7 +75,7 @@
>   
>   struct spi_engine_program {
>   	unsigned int length;
> -	uint16_t instructions[];
> +	uint16_t instructions[] __counted_by(length);
>   };
>   
>   /**
> @@ -115,9 +115,10 @@ struct spi_engine {
>   static void spi_engine_program_add_cmd(struct spi_engine_program *p,
>   	bool dry, uint16_t cmd)
>   {
> -	if (!dry)
> -		p->instructions[p->length] = cmd;
>   	p->length++;
> +
> +	if (!dry)
> +		p->instructions[p->length - 1] = cmd;
>   }
>   
>   static unsigned int spi_engine_get_config(struct spi_device *spi)